/*
 * This file contains the command processing functions for a number of random
 * commands. There is no functional grouping here, for sure.
 */

#include        <stdio.h>
#include        "ed.h"

int     tabsize;                        /* Tab size (0: use real tabs)  */

/*
 * Set fill column to n. 
 */
setfillcol(f, n)
{
        fillcol = n;
        return(TRUE);
}

/*
 * Display the current position of the cursor, in origin 1 X-Y coordinates,
 * the character that is under the cursor (in octal), and the fraction of the
 * text that is before the cursor. The displayed column is not the current
 * column, but the column that would be used on an infinite width display.
 * Normally this is bound to "C-X =".
 */
showcpos(f, n)
{
        register LINE   *clp;
        register long   nch;
        register int    cbo;
        register long   nbc;
        register int    cac;
        register int    ratio;
        register int    col;
        register int    i;
        register int    c;

        clp = lforw(curbp->b_linep);            /* Grovel the data.     */
        cbo = 0;
        nch = 0;
        for (;;) {
                if (clp==curwp->w_dotp && cbo==curwp->w_doto) {
                        nbc = nch;
                        if (cbo == llength(clp))
                                cac = '\n';
                        else
                                cac = lgetc(clp, cbo);
                }
                if (cbo == llength(clp)) {
                        if (clp == curbp->b_linep)
                                break;
                        clp = lforw(clp);
                        cbo = 0;
                } else
                        ++cbo;
                ++nch;
        }
        col = getccol(FALSE);                   /* Get real column.     */
        ratio = 0;                              /* Ratio before dot.    */
        if (nch != 0)
                ratio = (100L*nbc) / nch;
        mlwrite("X=%d Y=%d CH=0x%x .=%D (%d%% of %D)",
                col+1, currow+1, cac, nbc, ratio, nch);
        return (TRUE);
}

/*
 * Return current column.  Stop at first non-blank given TRUE argument.
 */
getccol(bflg)
int bflg;
{
        register int c, i, col;
        col = 0;
        for (i=0; i<curwp->w_doto; ++i) {
                c = lgetc(curwp->w_dotp, i);
                if (c!=' ' && c!='\t' && bflg)
                        break;
                if (c == '\t')
                        col |= 0x07;
                else if (c<0x20 || c==0x7F)
                        ++col;
                ++col;
        }
        return(col);
}

/*
 * Twiddle the two characters on either side of dot. If dot is at the end of
 * the line twiddle the two characters before it. Return with an error if dot
 * is at the beginning of line; it seems to be a bit pointless to make this
 * work. This fixes up a very common typo with a single stroke. Normally bound
 * to "C-T". This always works within a line, so "WFEDIT" is good enough.
 */
twiddle(f, n)
{
        register LINE   *dotp;
        register int    doto;
        register int    cl;
        register int    cr;

        dotp = curwp->w_dotp;
        doto = curwp->w_doto;
        if (doto==llength(dotp) && --doto<0)
                return (FALSE);
        cr = lgetc(dotp, doto);
        if (--doto < 0)
                return (FALSE);
        cl = lgetc(dotp, doto);
        lputc(dotp, doto+0, cr);
        lputc(dotp, doto+1, cl);
        lchange(WFEDIT);
        return (TRUE);
}

/*
 * Quote the next character, and insert it into the buffer. All the characters
 * are taken literally, with the exception of the newline, which always has
 * its line splitting meaning. The character is always read, even if it is
 * inserted 0 times, for regularity. Bound to "M-Q" (for me) and "C-Q" (for
 * Rich, and only on terminals that don't need XON-XOFF).
 */
quote(f, n)
{
        register int    s;
        register int    c;

        c = (*term.t_getchar)();
        if (n < 0)
                return (FALSE);
        if (n == 0)
                return (TRUE);
        if (c == '\n') {
                do {
                        s = lnewline();
                } while (s==TRUE && --n);
                return (s);
        }
        return (linsert(n, c));
}

/*
 * Set tab size if given non-default argument (n <> 1).  Otherwise, insert a
 * tab into file.  If given argument, n, of zero, change to true tabs.
 * If n > 1, simulate tab stop every n-characters using spaces. This has to be
 * done in this slightly funny way because the tab (in ASCII) has been turned
 * into "C-I" (in 10 bit code) already. Bound to "C-I".
 */
tab(f, n)
{
        if (n < 0)
                return (FALSE);
        if (n == 0 || n > 1) {
                tabsize = n;
                return(TRUE);
        }
        if (! tabsize)
                return(linsert(1, '\t'));
        return(linsert(tabsize - (getccol(FALSE) % tabsize), ' '));
}

/*
 * Open up some blank space. The basic plan is to insert a bunch of newlines,
 * and then back up over them. Everything is done by the subcommand
 * procerssors. They even handle the looping. Normally this is bound to "C-O".
 */
openline(f, n)
{
        register int    i;
        register int    s;

        if (n < 0)
                return (FALSE);
        if (n == 0)
                return (TRUE);
        i = n;                                  /* Insert newlines.     */
        do {
                s = lnewline();
        } while (s==TRUE && --i);
        if (s == TRUE)                          /* Then back up overtop */
                s = backchar(f, n);             /* of them all.         */
        return (s);
}

/*
 * Insert a newline. Bound to "C-M". If you are at the end of the line and the
 * next line is a blank line, just move into the blank line. This makes "C-O"
 * and "C-X C-O" work nicely, and reduces the ammount of screen update that
 * has to be done. This would not be as critical if screen update were a lot
 * more efficient.
 */
newline(f, n)
{
        int nicol;
        register LINE   *lp;
        register int    s;

        if (n < 0)
                return (FALSE);
        while (n--) {
                lp = curwp->w_dotp;
                if (llength(lp) == curwp->w_doto
                && lp != curbp->b_linep
                && llength(lforw(lp)) == 0) {
                        if ((s=forwchar(FALSE, 1)) != TRUE)
                                return (s);
                } else if ((s=lnewline()) != TRUE)
                        return (s);
        }
        return (TRUE);
}

/*
 * Delete blank lines around dot. What this command does depends if dot is
 * sitting on a blank line. If dot is sitting on a blank line, this command
 * deletes all the blank lines above and below the current line. If it is
 * sitting on a non blank line then it deletes all of the blank lines after
 * the line. Normally this command is bound to "C-X C-O". Any argument is
 * ignored.
 */
deblank(f, n)
{
        register LINE   *lp1;
        register LINE   *lp2;
        register int    nld;

        lp1 = curwp->w_dotp;
        while (llength(lp1)==0 && (lp2=lback(lp1))!=curbp->b_linep)
                lp1 = lp2;
        lp2 = lp1;
        nld = 0;
        while ((lp2=lforw(lp2))!=curbp->b_linep && llength(lp2)==0)
                ++nld;
        if (nld == 0)
                return (TRUE);
        curwp->w_dotp = lforw(lp1);
        curwp->w_doto = 0;
        return (ldelete(nld));
}

/*
 * Insert a newline, then enough tabs and spaces to duplicate the indentation
 * of the previous line. Assumes tabs are every eight characters. Quite simple.
 * Figure out the indentation of the current line. Insert a newline by calling
 * the standard routine. Insert the indentation by inserting the right number
 * of tabs and spaces. Return TRUE if all ok. Return FALSE if one of the
 * subcomands failed. Normally bound to "C-J".
 */
indent(f, n)
{
        register int    nicol;
        register int    c;
        register int    i;

        if (n < 0)
                return (FALSE);
        while (n--) {
                nicol = 0;
                for (i=0; i<llength(curwp->w_dotp); ++i) {
                        c = lgetc(curwp->w_dotp, i);
                        if (c!=' ' && c!='\t')
                                break;
                        if (c == '\t')
                                nicol |= 0x07;
                        ++nicol;
                }
                if (lnewline() == FALSE
                || ((i=nicol/8)!=0 && linsert(i, '\t')==FALSE)
                || ((i=nicol%8)!=0 && linsert(i,  ' ')==FALSE))
                        return (FALSE);
        }
        return (TRUE);
}

/*
 * Delete forward. This is real easy, because the basic delete routine does
 * all of the work. Watches for negative arguments, and does the right thing.
 * If any argument is present, it kills rather than deletes, to prevent loss
 * of text if typed with a big argument. Normally bound to "C-D".
 */
forwdel(f, n)
{
        if (n < 0)
                return (backdel(f, -n));
        if (f != FALSE) {                       /* Really a kill.       */
                if ((lastflag&CFKILL) == 0)
                        kdelete();
                thisflag |= CFKILL;
        }
        return (ldelete(n, f));
}

/*
 * Delete backwards. This is quite easy too, because it's all done with other
 * functions. Just move the cursor back, and delete forwards. Like delete
 * forward, this actually does a kill if presented with an argument. Bound to
 * both "RUBOUT" and "C-H".
 */
backdel(f, n)
{
        register int    s;

        if (n < 0)
                return (forwdel(f, -n));
        if (f != FALSE) {                       /* Really a kill.       */
                if ((lastflag&CFKILL) == 0)
                        kdelete();
                thisflag |= CFKILL;
        }
        if ((s=backchar(f, n)) == TRUE)
                s = ldelete(n, f);
        return (s);
}

/*
 * Kill text. If called without an argument, it kills from dot to the end of
 * the line, unless it is at the end of the line, when it kills the newline.
 * If called with an argument of 0, it kills from the start of the line to dot.
 * If called with a positive argument, it kills from dot forward over that
 * number of newlines. If called with a negative argument it kills backwards
 * that number of newlines. Normally bound to "C-K".
 */
kill(f, n)
{
        register int    chunk;
        register LINE   *nextp;

        if ((lastflag&CFKILL) == 0)             /* Clear kill buffer if */
                kdelete();                      /* last wasn't a kill.  */
        thisflag |= CFKILL;
        if (f == FALSE) {
                chunk = llength(curwp->w_dotp)-curwp->w_doto;
                if (chunk == 0)
                        chunk = 1;
        } else if (n == 0) {
                chunk = curwp->w_doto;
                curwp->w_doto = 0;
        } else if (n > 0) {
                chunk = llength(curwp->w_dotp)-curwp->w_doto+1;
                nextp = lforw(curwp->w_dotp);
                while (--n) {
                        if (nextp == curbp->b_linep)
                                return (FALSE);
                        chunk += llength(nextp)+1;
                        nextp = lforw(nextp);
                }
        } else {
                mlwrite("neg kill");
                return (FALSE);
        }
        return (ldelete(chunk, TRUE));
}

/*
 * Yank text back from the kill buffer. This is really easy. All of the work
 * is done by the standard insert routines. All you do is run the loop, and
 * check for errors. Bound to "C-Y". The blank lines are inserted with a call
 * to "newline" instead of a call to "lnewline" so that the magic stuff that
 * happens when you type a carriage return also happens when a carriage return
 * is yanked back from the kill buffer.
 */
yank(f, n)
{
        register int    c;
        register int    i;
        extern   int    kused;

        if (n < 0)
                return (FALSE);
        while (n--) {
                i = 0;
                while ((c=kremove(i)) >= 0) {
                        if (c == '\n') {
                                if (newline(FALSE, 1) == FALSE)
                                        return (FALSE);
                        } else {
                                if (linsert(1, c) == FALSE)
                                        return (FALSE);
                        }
                        ++i;
                }
        }
        return (TRUE);
}